I have an old Apple PowerBook G4 with a broken CD/DVD drive. For most practical purposes, the broken drive is no issue. However, if you're going to re-install the laptop, it becomes one. Luckily, the PowerBook is able to boot from USB...
At first, I tried following the instructions on "LiveUSB on PPC" found in Gentoo's Wiki, but that didn't work out at first. I then found a blog entry titled "Creating a bootable USB Stick with Mac OS X in 10 easy steps". Combining the two lead to success, so here's what I did:
I downloaded the latest PowerPC release of Finnix, a " self-contained, bootable Linux CD distribution" from the project's front page.
I re-named the ISO image from finnix-ppc-105.iso to finnix-ppc-105.dmg. Also, I displayed the file's information in Finder by right-clicking on the file icon and selecting "Show Information". I doubt that this step is required but it certainly didn't do any harm.
From a shell, aka "Terminal Window", I used the command diskutil list to find the device path to my USB drive. In my case, it was /dev/disk6.
- I then unmounted the drive by running
$ diskutil unmountDisk /dev/disk6
- Using good, old dd(1), I wrote the disk image to the USB drive:
$ sudo dd if=finnix-ppc-105.dmg of=/dev/disk6 bs=1m
- Finnally, I unmounted the drive by running:
$ diskutil eject /dev/disk6
In order to boot the PowerBook from the USB drive, I had to drop into Open Firmware. In case you didn't know it, this is done by holding down Cmd+Option+o+f right after the computer is turned on.
The next step was to find the device node of the bootable USB drive. To do this, I browsed the device tree for any USB node that had a disk child node.
> dev / > lsIn my case, the USB drive was at /pci@f2000000/usb@1b,1/disk@1.
The instruction found on the Gentoo wiki assign the cd alias to that node, so I did that, too, by running:
> devalias cd /pci@f2000000/usb@1b,1/disk@1
This allowed me to finally boot from the USB drive like this:
> boot cd:,\\:tbxi